1. Field
This disclosure generally relates to manufacturing composite parts, and deals more particularly with a method and apparatus for co-curing composite skins and stiffeners in an autoclave.
2. Background
It is sometimes necessary to cure multiple composite parts in an autoclave which require internal bladders to prevent them from collapsing under autoclave pressure. For example, in the aircraft industry, a composite skin may be compressed against and co-cured with multiple stiffeners having a hat shaped cross-section using a vacuum bag and autoclave pressure. In order to avoid collapsing under the autoclave pressure, the bladders may be vented to the autoclave environment so that the internal pressure in the bladders is substantially that applied by the autoclave. One technique for venting the bladders is to place holes in the bladders which are vented through the vacuum bag. Venting the bladders through the vacuum bag increases the possibility of leakage into the bag, and can also lead to undesirable pre-loading of vent pipes, as well as potential distortion of fiber stiffeners during curing, and possible resin starvation issues.
It would be desirable to provide a method and apparatus for co-curing composite skins and stiffeners which avoid the need for venting the bladders through the vacuum bag while promoting substantially even distribution of autoclave pressure to the bladders. There is also a need for apparatus as described above which may be easily reconfigured for use with differing types of part assemblies.